Circular RNA CDK6 suppresses cervical cancer proliferation and metastasis by sponging miR-449a

miR-449a: A Promising Biomarker and Therapeutic Target in Cancer and Other Diseases

In the regulation of gene expression, epigenetic factors like non-coding RNAs (ncRNAs) play an equal role in genetics. The role of microRNAs (miRNAs), which are members of the ncRNA family, in post-transcriptional gene regulation is well-documented and has important implications for both normal and abnormal biological processes, such as angiogenesis, proliferation, survival, and apoptosis. The purpose of this study was to synthesize previous research on miR-449a by analyzing published results from various databases, as there have been a number of investigations on miR-449's potential involvement in the development of human disorders. Based on our findings, miR-449 is strongly dysregulated in a wide range of diseases, from various cancers to cardiovascular diseases, cognitive impairments, and respiratory diseases, and it may play a pivotal role in the development of these problems. In addition, miR-449a functions as a crucial regulator of the expression of several well-known genes, including E2F-3, BCL2, NOTCH1, and SOX4. This, in turn, modulates various pathways and processes related to cancer, including Notch, PI3K, and TGF-β, and contributes to the improvement of cancer drug sensitivity. Curiously, abnormalities in the expression of this miRNA may serve as diagnostic or prognostic indicators for distinguishing between healthy people and patients or to evaluate the survival rates for specific disorders. This article provides a synopsis of the current understanding of miR-449a's role in human disease development through its regulation of gene expression and the biological processes related to these genes and their linked processes. In addition, we have covered the topic of miR-449a's potential as a clinical feature (diagnosis and prognosis) indicator for a range of disorders, both neoplastic and non-neoplastic. In general, our goal was to gain a thorough comprehension of the numerous functions of miR-449a in different disorders.

Circular RNAs in EMT-driven metastasis regulation: modulation of cancer cell plasticity, tumorigenesis and therapy resistance

The non-coding RNAs comprise a large part of human genome lack of capacity in encoding functional proteins. Among various members of non-coding RNAs, the circular RNAs (circRNAs) have been of importance in the pathogenesis of human diseases, especially cancer. The circRNAs have a unique closed loop structure and due to their stability, they are potential diagnostic and prognostic factors in cancer. The increasing evidences have highlighted the role of circRNAs in the modulation of proliferation and metastasis of cancer cells. On the other hand, metastasis has been responsible for up to 90% of cancer-related deaths in patients, requiring more investigation regarding the underlying mechanisms modulating this mechanism. EMT enhances metastasis and invasion of tumor cells, and can trigger resistance to therapy. The cells demonstrate dynamic changes during EMT including transformation from epithelial phenotype into mesenchymal phenotype and increase in N-cadherin and vimentin levels. The process of EMT is reversible and its reprogramming can disrupt the progression of tumor cells. The aim of current review is to understanding the interaction of circRNAs and EMT in human cancers and such interaction is beyond the regulation of cancer metastasis and can affect the response of tumor cells to chemotherapy and radiotherapy. The onco-suppressor circRNAs inhibit EMT, while the tumor-promoting circRNAs mediate EMT for acceleration of carcinogenesis. Moreover, the EMT-inducing transcription factors can be controlled by circRNAs in different human tumors.

Hsa_circ_0000078 Regulates miR-205-5p/EREG Pathway to Inhibit Cervical Cancer Progression

It is well established that circular RNAs (circRNAs) play a role in tumor initiation and tumorigenesis. The goal of this study was to reveal the detailed functions and regulatory mechanisms of circ_0000078 in cervical cancer (CC). Circ_0000078, miR-205-5p, and epiregulin (EREG) mRNA expression levels were examined using RT-qPCR. Western blotting was performed to quantify EREG protein. Cell proliferation, apoptosis, migration, and invasion were examined by performing CCK-8, caspase 3 activity, wound healing, and transwell assays, respectively. The effect of circ_0000078 on tumor growth in vivo was confirmed in a xenograft model. The putative relationship between miR-205-5p and circ_0000078 or EREG, as predicted by bioinformatics analysis, was evaluated by dual-luciferase and RNA immunoprecipitation assays. Aberrant downregulation of circ_0000078 and EREG as well as upregulation of miR-205-5p were observed in cervical tumor samples and cancer cells. Ectopic expression of circ _0000078 not only restrained cancer cell growth, survival, migration, and invasiveness, but also decelerated tumor formation and development in a mouse model. miR-205-5p, acts as a target of circ_0000078 and directly binds to EREG to repress its expression. Overexpression of miR-205-5p reversed the inhibitory effects of circ_0000078 upregulation on cancer cell behavior and also partially abolished the anti-cancer effects of EREG upregulation in vitro. Circ_0000078 inhibits the growth of cancer by interfering with the miR-205-5p/EREG network, acting as a tumor suppressor in CC. These results provide a better understanding of the pathogenesis of this disease.

Advances in epigenetic modifications and cervical cancer research

Cervical cancer (CC) is an important public health problem for women, and perspectives and information regarding its prevention and treatment are quickly evolving. Human papilloma virus (HPV) has been recognized as a major contributor to CC development; however, HPV infection is not the only cause of CC. Epigenetics refers to changes in gene expression levels caused by non-gene sequence changes. Growing evidence suggests that the disruption of gene expression patterns which were governed by epigenetic modifications can result in cancer, autoimmune diseases, and various other maladies. This article mainly reviews the current research status of epigenetic modifications in CC based on four aspects, respectively DNA methylation, histone modification, noncoding RNA regulation and chromatin regulation, and we also discuss their functions and molecular mechanisms in the occurrence and progression of CC. This review provides new ideas for early screening, risk assessment, molecular targeted therapy and prognostic prediction of CC.

Long non-coding RNA HOXA11-AS knockout inhibits proliferation and overcomes drug resistance in ovarian cancer

In ovarian carcinogenesis and progression, long non-coding RNAs (lncRNAs) have been shown to have a role, although the underlying processes remain a mystery. By modulating the degree of autophagy in ovarian cancer cells, we sought to learn more about the function lncRNA HOXA11-AS plays in the development of ovarian cancer. The expression of HOXA11-AS in ovarian normal cells and ovarian cancer cell lines was measured using R package and qRT-PCR. Ovarian cancer cells expressed HOXA11-AS substantially higher than normal cells, while cisplatin-resistant cells expressed HOXA11-AS significantly higher than ovarian cancer cells. Next, we studied the prognostic data of HOXA11-AS in ovarian cancer in the Tissue Cancer Genome Atlas (TCGA). In the next step, lentiviral transfection of ovarian cancer cells A2780, OVCAR3, and A2780/DDP (cisplatin-resistant) were performed, and HOXA11-AS knockdown was found to significantly inhibit cell viability, migration, and invasion of A2780 and OVCAR3 cells, and promote apoptosis by CCK-8 assay, transwell assay, cell cycle, and apoptosis assay, and promoted the sensitivity of A2780/DDP cells to cisplatin. It has been shown by the western blot test that HOXA11-AS knockdown increases the amount of cellular autophagy in cells. In contrast, adding the autophagy inhibitor 3-methyladenine (3-MA) to HOXA11-AS cells knocked down in vivo reduced its anti-tumor properties. As a whole, this study found that HOXA11-AS knockdown increased the expression of autophagy-related proteins and improved cisplatin sensitivity, decreased ovarian cancer cell proliferation, and promoted cell apoptosis. This study provides new insights into the role of HOXA11-AS in ovarian cancer regulation.